The technical field is power supplies for electrical and electronic devices, and in particular, wireless power supplies for powering electronic devices such as personal computers.
Many electrical and electronic devices cannot be used in certain geographical regions because of the absence of AC or DC power to operate the devices. Other electronic or electrical devices are restricted geographically because the power supplies in these devices do not conform to the available power in terms of voltage and/or frequency. One solution is to produce portable versions of the electrical and electronic devices that can operate on self-contained power supplies, such as nickel-cadmium batteries or the like. Recently, fuel cell technology has been adapted to provide power for the portable electronic devices. U.S. Pat. No. 6,057,051 discloses a miniaturized fuel cell assembly that can be adapted for use in a portable, or laptop computer. U.S. Pat. No. 5,759,712 discloses a miniature fuel cell that can be adapted to a variety of purposes to power portable electronic devices, such as cellular telephones.
The above-noted patents disclose solutions for powering portable electronic devices. Because they are intended to be portable, the electronic devices must be designed to include specific features, such as light weight, small size, and most importantly, low power consumption. Thus, the design of a portable electronic device necessarily considers the availability of a power supply that can fit the device""s design parameters of light weight and small size, and yet can deliver sufficient power to operate the device for a sustained period. Such design constraints (portability, low power consumption) often lead to lower performance capabilities compared to corresponding non-portable devices, and to greatly increased costs of manufacture.
While electrical and electronic devices that are not designed to be portable (including design limits on power consumption) cannot be used in geographical regions where power is unavailable, these non-portable devices also are generally less expensive to manufacture, and provide for better performance than their portable counterparts. For example, a desktop personal computer may operate at a higher clock speed, have a larger memory and mass storage, and cost less, than a laptop, or portable personal computer. Thus, achieving the best performance at the lowest cost is not consistent with the concept of portability.
A retrofittable power supply allows an electronic device that is initially designed to be non-portable (in the sense that such electronic and electrical devices require a wired connection to an AC or DC power supply) to operate in geographical regions, or under conditions, in which a wired power supply is not available. The retroffitable power supply can simply plug into an existing case or frame of the non-portable electronic device, and can then serve as a means for powering both the non-portable electronic device, as well as a means for powering peripheral devices that may be coupled to the non-portable electronic device.
In an embodiment, the retrofittable power supply comprises a housing having a form factor equivalent to a conventional, wired power supply. The housing includes a power generation section. The power generation section may comprise a fuel cell, or otherwise incorporate advanced fuel cell technology. The power generation section may include, as part of the fuel cell, a water holding and disposal module. The water holding and disposal module may comprise water absorption means, which may include commercially available materials that absorb and hold water generated by the fuel cell. The water holding and disposal module may also include a water tank to hold excess water generated by the fuel cell. The water holding and disposal module may also include means for disposal of excess water. In an embodiment, the water disposal means comprises a fan that accelerates evaporation of the excess water. Alternatively, or in addition, heat generated by operation of the fuel cell may be used to speed evaporation. In another embodiment, excess water may be drained from the water holding and disposal module. Such drainage may be facilitated by a manually or automatically operated valve, and a piping arrangement that diverts the draining water from components of the non-portable electronic device.
The retroffitable power supply may also comprise DC/AC power converter to supply AC power. The AC power may be supplied at one or more AC power out fixtures to enable operation of peripheral devices associated with the non-portable electronic device.
In another embodiment, the retrofittable power supply may include a power storage module. The power storage module may be a rechargeable battery, for example. The power generation module then provides DC power to the power storage module for subsequent delivery to one or more components of the non-portable electronic device or to one or more peripheral devices.
A specific application of the retrofittable power supply is to replace a conventional, wired power supply in a desktop personal computer. The conventional, wired power supply is simply removed, and is replaced by the retrofittable power supply. The AC power out section of the retrofittable power supply provides AC power to peripheral devices such as a monitor and a printer, for example. When using a fuel cell in the power generation module, the fuel source will eventually have to be replenished. This may be accomplished by replacing the entire retrofittable power supply with a new retrofittable power supply. Alternatively, a fuel supply in the fuel cell may simply be renewed. For example, in a fuel cell using liquid methanol carried in a fuel tank, the tank can be refilled or simply replaced.
Other power sources besides fuel cells may be used in the power generation module. For example, the power generation module may use a radioactive material, such as plutonium 239, to generate heat energy, which is then converted into electrical energy. Other possible power generation means can include small turbines or solar devices. Power storage means may include, in addition to conventional batteries, fly wheel storage devices, and devices that convert the heat generated by operation of the fuel cell into electrical power for subsequent storage.